I have a TableRow with a custom background. When I click and hold my finger down, then drag out of the row and release without selecting anything (and thus generating a click event), the dark lines above and below the TableRow aren't being redrawn.
What even should I listen for, or, how might I refresh this Table so that the rows are redrawn if a touch is detected, but no selection is actually made?
Thanks everybody,
Tony
If you want to detect touch events (for a realease), can refer MotionEvent in Android, you have to override onTouchEvent(MotionEvent e)
You will get events for the Touch and then can match the action of the event (event.getAction) to ACTION_DOWN and ACTION_UP(for when touch is released)
Eg.
public boolean onTouch(View v, MotionEvent e) {
if (e.getAction() == MotionEvent.ACTION_UP) {
//can check if selection is made or not and add function accordingly
return true;
} else {
return false;
}
}
How many columns do you have in your table, depending on your requirement, you can look up the ListView and custom adapter implementation with a notifySetDataChanged...check:
http://www.vogella.com/tutorials/AndroidListView/article.html
Related
Is it possible to know in a ListView if a item is pressed / touched (but not clicked) and know which?
I tried with "OnTouchListener" but without success (I can intercept UP and Down events on the ListView but not on the elements).
I tried also "OnItemLongClickListener" but I have to wait when I want information immediately.
Do you have an idea ?
Thank you in advance.
Edit (solution) :
I put the following code in my adapter in the item view.
view.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
image.setImageResource(R.drawable.image2);
}
else if (event.getAction() == MotionEvent.ACTION_UP) {
image.setImageResource(R.drawable.image1);
}
return true;
}
});
And now, when I touch an item, the picture becomes "image2" and when I do not touch the screen, it returns to "image1".
But there is a problem, if I press an item (the image2 appears well) and I move my finger in the list view and I do not touch the screen, it stays on for the image2, "MotionEvent.ACTION_UP" could not execute.
Do you have any idea how to do that as soon as I do not touch the screen, it must return on image1?
Thank you for your help.
You can set SetOnTouchListener to item view when your adapter create it.
you just try yo implement the Listener then you can override the function or please add your rough work part
I use onTouch as it is the best and more modifiable than for an instance onClick. It is a custom view that is being touched that I want to respond with action, and I have allready limited so you can't just touch and it does it over and over. Now I need it to limit the amount of simountanious taps.
EDIT:
#Override
public boolean onTouch(View v, MotionEvent event) {
lines++;
return false;
}
I have prevented constant action, but not the possibility to press with more than 1 finger, so that if you tap with more the rest of the fingers get ignored
There are several ways to do it.
best for you may be limit it inside in your overrided onTouch event.
if(event.getPointerCount() > 1) {
System.out.println("Multitouch detected!");
return true;
}
else
return super.onTouchEvent(event);
Another option is set attribute android:splitMotionEvents = false in your xml file.
I have a ListView. Inside the cells, I have a custom view. (You can draw in it.)
When drawing, I turn off scrolling of the list ..
theListView.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View v, MotionEvent event)
{
if (event.getAction() == MotionEvent.ACTION_MOVE)
{
if ( STATE.weAreDrawoning )
{
return true;
// so, do not forward and hence do not scroll the list
}
else
{
return false;
}
}
return false;
}
});
That's fine. But strangely, up-down touching in the custom View, is still passed on to the list and makes it scroll.
public class AmazingCustomView extends View
{
blah
#Override
public boolean onTouchEvent(MotionEvent event)
{
blah
return true;
}
}
notice in the custom view onTouchEvent is returning true (I also tried false! :) )
but the motion events appear to be still passed on .. what gives??
Is there another "on .. something" I'm missing in the custom view? Sorry, new to Android and lame. Thanks!
PS, I tried turning on "clickable" on the xml of the custom view, didn't help :O
--
Worse ...
I've just realised ALL controls in the ListView, say buttons, still "pass on scrolling"
I fear the system I use above for turning off scrolling is just no good. :/
important...
For anyone googling to here. The only real way I've found to turn off scrolling on an android listView ...
danosipov.com/?p=604
(don't forget to separately turn off your pull-to-refresh)
You may need to override onInterceptTouchEvent. Its an odd function, documentation here: http://developer.android.com/reference/android/view/ViewGroup.html#onInterceptTouchEvent%28android.view.MotionEvent%29
Problem description:
I have a TextView on a RelativeLayout and I want to color it red when the user touches it, and go on another page when he clicks on it.
So I tried to set an OnClickListener to do the click, and an OnTouchListener to implement the touch function (MotionEvent.ACTION_DOWN) but this combination doesn't work, because OnTouchListener makes OnClickListener non-functional (don't know why).
On forums people say that we can implement the OnClick by the OnTouch MotionEvent.ACTION_UP, but this one can be triggered out of my TextView layout (the TextView gonna be clicked if you press it and drag your finger out of him to release) and this is not the desired behavior because I want:
click = press + release on the TextView.
Can someone give me a solution for this please?
you may call View.performClick() when action_up. Hope it helps.
your_txtView.setOnClickListener(new TextView.OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
your_txtView.setOnTouchListener(new TextView.OnTouchListener(){
#Override
public boolean onTouch(View v, MotionEvent event) {
if (MotionEvent.ACTION_DOWN == event.getAction()) {
} else if (MotionEvent.ACTION_UP == event.getAction()) {
v.performClick();
}
return true;
}
});
Adel, is the problem with the first click, or you don't get any click at all?
There is this issue if you have multiple clickable layout you don't get any click events for the first. That's because it makes it first selected and then you get the click event, try the below code.
private class CustomTouchListener implements OnTouchListener {
#Override
public boolean onTouch(View v, MotionEvent event) {
TextView tv = (TextView) v.findViewById(R.id.single_line_text);
if (event.getAction() == MotionEvent.ACTION_DOWN) {
tv.setTextColor(COLOR_WHEN_PRESSED);
} else if (event.getAction() == MotionEvent.ACTION_UP) {
tv.setTextColor(COLOR_WHEN_RELEASED);
// Action of click goes here
} else if (event.getAction() == MotionEvent.ACTION_CANCEL) {
tv.setTextColor(COLOR_WHEN_RELEASED);
// To handle release outside the layout region
}
return false;
}
}
This is working in my current implementation if you set the touch listener for your layout.
You also need to set below on your layout
android:focusable="true"
android:focusableInTouchMode="true"
android:clickable="true"
Hope it helps!!!
EDIT: Additionally, there should be a flag in both DOWN and UP. Set it in DOWN and check if its set in UP. This will avoid a bug where user might tap anywhere in the screen and then hover on your textview and release it.
Had the same problem. Solved it by returning false from ACTION_MOVE. I've been fighting with it for few hours, trying various things, but seems like i've kept overlooking this little issue... And now it makes sense. When you return true from onTouch, futher processing is stopped, so that OnClickListener is not aware of any movements and triggers onClick even after pointer have moved outside of view.
Given that there is a ViewGroup with several children. As for this ViewGroup, I'd like to have it managing all MotionEvent for its all children, which says VG will
1. be able to intercept all events before they get dispatched to target (children)
2. VG will first consume the event, and determine if will further dispatch event to target child
3. DOWN, MOVE, UP, I'd like to see them as relatively independent, which means VG could eat DOWN, but give MOVE and UP to children.
I've read SDK guide "Handling UI Event", I knew event listeners, handlers, ViewGroup.onInterceptTouchEvent(MotionEvent), and View.onTouchEvent(MotionEvent).
Here's my sample,
#Override
public boolean onInterceptTouchEvent (MotionEvent event) {
if (MotionEvent.ACTION_DOWN == event.getAction()) {
return true;
}
return super.onInterceptTouchEvent(event);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if (MotionEvent.ACTION_DOWN == event.getAction()) {
return true;
}
else {
if (!consumeEvent(event)) {
// TODO: dispatch to target since I didn't want to eat event
//return this.dispatchTouchEvent(event); // infinite loop!!!
}
}
return super.onTouchEvent(event);
}
To be able to eat some events, I have to return true in above both methods when DOWN event occurred, because SDK said so. Then I could see MOVE and up in onTouchEvent. However, in my case, I've no idea about how to dispatch event to children.
Above dispatchTouchEvent led to infinite loop, which was understandable, since VG itself might be the target. I can't tell which would be target at that moment, MotionEvent didn't give a hint, so dispatchTouchEvent was totally useless.
Anyone help me out? Thanks.
There is no easy way to find the source View from onInterceptTouchEvent, nor there is a way to "dispatch" these events. You can dispatch KeyEvents, but not MotionEvents.
A common way to deal with MotionEvents (e.g., for drag and drop) is to handle the MotionEvent.ACTION_DOWN events by the different Views (through the onTouch callback after implementing OnTouchListener), and the MotionEvent.ACTION_MOVE events through the parent Viewgroup's onInterceptTouchEvent method.
But some LOCs say a lot more than a bunch of words. There's a very nice example of what I'm saying here: http://doandroids.com/blogs/tag/codeexample/
If you handle the ACTION_DOWN event in the View itself, then you can store which View started it elsewhere and use that variable for further actions. The Event is bound to the same View until is finished by an ACTION_UP or an ACTION_CANCEL actions.
If you need to keep track the View and execute an action on the ViewGroup during the ACTION_DOWN, then I suggest you to add a public method in your ViewGroup (e.g. public boolean handleActionDown (View v, MotionEvent e) that will be called from the onTouch callback